The Blues were badly running out of ideas, with Abu Kamara the chief culprit towards the end, as the match threatened to peter out for a frustrating goalless draw.
But Kamara was brought down and unpopular referee Craig Hicks pointed to the spot for Bishop to net – and here are our Pompey player ratings...
1. Will Norris - 7
Had absolutely nothing to do all game, including barely asked to claim a cross. Some impressive distribution at times too. Photo: Jason Brown
2. Terry Devlin - 7
Wasted a couple of great first-half chances popping up at the far post, but otherwise did well as a conventional right-back this week. Energy, enthusiasm and clearly has a bit of quality about him. Photo: Jason Brown
3. Sean Raggett - 8
Was winning an intriguing battle with Ikpeazu until the striker came off with a shoulder injury sustained in one of their clashes. Strong, uncompromising, absolutely dominant. Photo: Jason Brown
4. Conor Shaughnessy - 8
Back to his best after a little January dip. Had to win lots of headers and rock solid when challenged on the ground. In this form, he really is outstanding. Cracking tackle on Chislett to spark the move for the penalty. Photo: Jason Brown